A rare-earth nanocomposite magnet, in which a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase are mixed up together in a nano size (several nm to several tens of nm), can achieve high residual magnetization, coercive force, and maximum energy product owing to exchange interaction acting between a hard magnetic phase and a soft magnetic phase.
However a texture having both a hard magnetic phase and a soft magnetic phase has had a drawback in that magnetization reversal occurs in a soft magnetic phase and propagation of the magnetization reversal cannot be prevented which leads to low coercive force.
As a countermeasure, a nanocomposite magnet, in which the residual magnetization and coercive force are improved by forming a 3-phase texture with an intercalated R—Cu alloy phase (thickness unknown, R is one, or 2 or more kinds of rare-earth elements) between a Nd2Fe14B phase (hard magnetic phase) and an α-Fe phase (soft magnetic phase), and thereby preventing the magnetization reversal from propagation, is disclosed in Patent Literature 1.
However, there is another drawback in the texture according to Patent Literature 1, in that the R—Cu phase intercalated between a hard magnetic phase and a soft magnetic phase impedes exchange coupling between a hard magnetic phase and a soft magnetic phase, and moreover the intercalated R—Cu phase reacts with both the hard magnetic phase and the soft magnetic phase so as to extend the distance between the hard soft phase and the soft phase and inhibit good exchange coupling, resulting in low residual magnetization.